monomorphic or not?
simonpj at microsoft.com
Thu Mar 6 03:56:15 EST 2008
No, it's fine. compress is indeed monomorphic, but since it's called at exactly one type, namely Char, so it gets the monomorphic type [Char] -> [Char]. That is what the Haskell Report says. (Or tries to.)
| -----Original Message-----
| From: glasgow-haskell-users-bounces at haskell.org [mailto:glasgow-haskell-users-bounces at haskell.org] On Behalf Of
| John Meacham
| Sent: 06 March 2008 07:26
| To: glasgow-haskell-users at haskell.org
| Subject: monomorphic or not?
| if you notice this program has the line
| > compress = map toEnum . codes_to_ascii . encode
| It seems to me this should run afoul of the monomorphism restriction due
| to the unknown ambiguous type in Enum, but ghc 6.8.2 happily accepts it.
| Jhc thinks it is illegal according to my reading of the specification.
| Any ideas about what is going on here?
| John Meacham - ⑆repetae.net⑆john⑈
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